This paper presents a computational and semi-analytical approach for theoretical evaluation of solution-process-based optoelectronic devices, such as quantum dot (QD) infrared photodetectors. The dark current and photocurrent for infrared photodetectors… Click to show full abstract
This paper presents a computational and semi-analytical approach for theoretical evaluation of solution-process-based optoelectronic devices, such as quantum dot (QD) infrared photodetectors. The dark current and photocurrent for infrared photodetectors are extracted on the basis of the model presented here. In this model, two main mechanisms have been assumed to contribute to the current of the device: the electron tunneling in the confined states and the drift of electrons in the continuum states. For the former, the Landauer-Büttiker formalism, in which the transmission function was obtained through the Green's function method was used. However, the drift-diffusion model was applied for the latter while considering the trapping and detrapping roles of QDs. Furthermore, different geometrical effects have been analyzed, including the QDs' size distribution, the space between QDs, the system's length, and the system's width, on the device's parameters, such as the absorption coefficient, photoconductive gain, dark current, and detectivity. The results seem to point to a great dependency of the device's performance on these geometrical aspects. For example, the nonuniformity of the QDs' sizes have been shown to exert negative effects on the device's detectivity. In addition, it could noticeably influence the tunneling current, such as by decreasing the maximum value of the current.
               
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